#5 Nematodes (general info)

What is the abomasum?

The glandular, acidic fourth stomach chamber of ruminants

What happens when a nematode arrests?

They suspend their development at a specific stage, allowing them to remain dormant within the host for extended periods before resuming development

What is important about the Indirect Transmission Cycles?

Intermediate host is required

What is the life cycle of abomasal nematodes?

Eggs in feces → L1 → L2 → L3 on vegetation → ingested → adults establish in abomasum or small intestine

Prepatent period

Time from infection until egg shedding begins (~3+ weeks)

Patent period

Period when adults are producing viable eggs

Why do some species (e.g., Ostertagia) undergo arrested development?

To survive unfavorable environmental conditions and synchronize emergence when conditions improve

Edema

An excess accumulation of fluid in cells, tissues, or cavities

• often applied to the subcutaneous tissues

Bottle jaw

Submandibular edema caused by hypoproteinemia

Hypoproteinemia

abnormally low levels of protein (specifically albumin and globulin) in the blood

What does Hypoproteinemia indicate?

the body is losing too much protein

• not producing enough

• failing to absorb it

What does Hypoproteinemia often cause?

• swelling (edema)

• fatigue

• muscle loss

Abomasal Parasite Counts

Old technique trying to figure out the total count of the parasites

What is Abomasal Parasite Counts (APC)correlated with?

Higher deer density = higher parasite burdens (in SE U.S.)

Why are APCs less useful in the West?

Environmental conditions (soil moisture, humidity) influence larval survival more than deer density

Bronchitis

inflammation of the bronchial tubes (airways) in the lungs

• leading to swelling and excess mucus production

Hemorrhagic anemia

a type of anemia caused by the rapid or chronic loss of red blood cells due to bleeding

• Acute, sudden blood loss

Encephalitis

acute inflammation (swelling) of the brain tissue

Dyspnea

Difficult or labored breathing

Verminous pneumonia

inflammatory disease of the lower respiratory tract

Ataxia

Lack of muscular coordination; irregularity of muscle action

Peritonitis

inflammation of the peritoneum

• causes severe abdominal pain, swelling, and fever

Enteritis

inflammation of the small intestine

• causes significant morbidity and mortality

What is Enteritis typically characterized by?

• diarrhea

• dehydration

• weight loss

• lethargy

Paratenic hosts

secondary animal hosts that harbor larval parasites without allowing them to undergo significant development, maturation, or replication

• host that is still able to transmit the parasite, the parasite just won’t develop

Adhesions

• inflammation causing the excessive buildup of fibrous tissue-> scar tissue that inhibits the organs from moving

• Enough adhesions can cause a twisted gut

Conglomerate immunity

Ongoing immunity that keeps infection at bay

• doesn’t stop them from getting infected, just greatly minimizes the impact

Microfilariae

Early larval stage of parasitic filarial nematodes (roundworms) that circulate in the blood or tissues of infected wildlife

Cystacanth

infective, third-stage larva of Acanthocephalan worms that develops within an intermediate host